Flora of North America species comparison

Variety californicum occurs in both coastal and interior mountains of California from the northern South Coast Range and the northern Sierra Nevada to the mountains of southwestern California. Considerable variation exists in head size, corolla color, and in length and display of phyllary appendages. In several areas of its range, the predominantly white- to light purple-flowered var. californicum occurs with red-flowered var. venustum. These plants are highly interfertile (H. Wells 1983; D. J. Keil and C. E. Turner 1992). Introgressive hybridization among them has resulted in a variety of emergent phenotypes and may have contributed to the variation within var. californicum.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Variety venustum has the widest ecological range of the races of C. occidentale. Populations occur within a few miles of the California coast in the North and South Coast Ranges and western Transverse Range and range eastward across the state into scattered sites in the Sierra Nevada to the higher elevations of the arid mountains of the western Mojave Desert and adjacent areas of the southwestern Great Basin Desert. Most populations of these plants can be recognized by their striking red to reddish pink corollas. The heads are sometimes visited by hummingbirds as well as by a variety of insects. Intermediates have been documented between var. venustum and vars. californicum and candidissimum.

(Discussion copyrighted by Flora of North America; reprinted with permission.)